PHP Challenges: Compute the sum of the two reversed numbers and display the sum in reversed form

Last update on December 20 2024 10:22:19 (UTC/GMT +8 hours)

Write a PHP program to compute the sum of the two reversed numbers and display the sum in reversed form.

Input : 13, 14

Note : The result will not be unique for every number for example 31 is a reversed form of several numbers of 13, 130, 1300 etc. Therefore all the leading zeros will be omitted.

Explanation :

PHP: Compute the sum of the two reversed numbers and display the sum in reversed form

Sample Solution :

PHP Code :

<?php
// Function to find the reverse sum of two numbers
function reverse_sum($n1, $n2)
{
    // Return the sum of the reverse of both numbers
    return reverse_integer($n1) + reverse_integer($n2);
}

// Function to reverse an integer
function reverse_integer($n)
{
    // Initialize variable to store the reversed integer
    $reverse = 0;
    
    // Loop until the input number becomes 0
    while ($n > 0)
    {
        // Multiply the current reversed number by 10 and add the last digit of the input number
        $reverse = $reverse * 10;
        $reverse = $reverse + $n % 10;
        
        // Remove the last digit from the input number
        $n = (int)($n / 10);
    }
    
    // Return the reversed integer
    return $reverse;
}   

// Test the reverse_sum function with different inputs and print the results
print_r(reverse_sum(13, 14) . "\n");
print_r(reverse_sum(130, 1) . "\n");
print_r(reverse_sum(305, 794) . "\n");
?>

Explanation:

Here is a brief explanation of the above PHP code:

Function definition:

The code defines a function named "is_geometric()" which checks if an array forms a geometric sequence. It takes an array '$arr' as input.

Inside the function:

It first checks if the array size is 1 or less. If so, it returns 'True' as any sequence with 1 or fewer elements is considered geometric.
It calculates the ratio between the second and first elements of the array.
It iterates through the array elements starting from the second element.
Within each iteration, it checks if the ratio of the current element to the previous element is equal to the initial ratio calculated.
If any ratio is not equal to the initial ratio, it returns "Not a geometric sequence".
If all ratios are equal, it returns "Geometric sequence".

Function Call & Testing:

Two arrays '$my_arr1' and '$my_arr2' are defined with different sets of numbers.
The "is_geometric()" function is called twice with these arrays as input.
Finally, "print_r()" function displays whether each input array forms a geometric sequence.

Sample Output:

72                                                          
32                                                          
1000

Flowchart:

PHP Code Editor:

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